This invention relates generally to nasal cannula therapy, and more particularly to improvements concerning fluid flow in nasal cannula therapy systems.
Nasal continuous positive airway pressure, NCPAP, is a used standard for administration of non-invasive positive airway pressure in the Neonate. Historically, Nasal Cannulae have been used at low flow rates (<1.5 1 pm) during infant weaning from assisted ventilation, or for maintenance in the sub-acute phase of chronic lung disease. Difficulty in regulation of pressure, and concerns regarding the damaging effects of inadequately warmed and humidified oxygen delivery systems on nasal mucosa, precluded the use of these devices in the more acute phases of respiratory distress and at the higher liter flow rates that would have been required to generate the pressures necessary to provide for that particular disease process. Certain devices held the promise of improved humidification and warming of the cannula flow, but introduced the possible deleterious effect of unknown pressure propagation as well as reported bacteria contamination of the circuit.
Accordingly, there was concern about delivering pressures that were excessive and possibly damaging to the respiratory tract, sinuses, ear drum or GI tract. Mechanical ventilators used for monitoring for pressures and flow were excessively expensive to supply and operate.